1. Field of the Invention
The present invention relates to a light-sensitive silver halide emulsion and a photographic light-sensitive material which have high-gamma photographic characteristics, a good graininess, a high incubation resistance, and a high latent image stability.
2. Description of the Related Art
Methods of manufacturing and techniques of using tabular silver halide grains are disclosed in, e.g., U.S. Pat. Nos. 4,434,226, 4,439,520, 4,414,310, 4,433,048, 4,414,306, and 4,459,353, JP-A-59-994335 ("JP-A" means Unexamined Published Japanese Patent Application), JP-A-60-209445, and JP-A-63-151618. Known advantages of grains of this type are improvements in sensitivity including an improvement in spectral sensitization efficiency obtained by sensitizing dyes, a good sensitivity/graininess relationship, and an improvement in sharpness and in covering power derived from specific optical properties of tabular grains.
In addition, EP514,742A describes that an emulsion, in which a value (flatness) obtained by dividing the value of a mean equivalent-circle diameter by the square of a mean thickness is 8 or greater, and which has mono-dispersity by which the standard deviation of a grain size distribution is 10% or less, has high-gamma photographic properties and a good graininess.
The present inventors have examined emulsions with the above characteristics and found that they require further improvements in incubation resistance and latent image stability.